Brain cell findings pave way for new therapies

A newly-discovered function of a protein found in the brain could lead to a breakthrough in the treatment of motor neurone disease, researchers say.

The study - a joint research project between Otago University and the University of Aberdeen in Scotland - found a protein known as transforming growth factor beta 2 (TGF-2) appeared to regulate how motor neurons sent signals to neighbouring brain cells, Otago neurobiologist associate professor Ian McLennan said.

The mechanism could lead to new therapies for symptoms of motor neurone disease.

Prof McLennan said the discovery surprised the researchers.

"We did not predict this, and the finding fundamentally alters our understanding of how communication between cells in the brain's motor system is controlled," he said.

"It is also likely that this mechanism plays a role in other brain signalling systems."

The flow of information from cell to cell was previously thought to be controlled by the number of "packets" of neurotransmitter chemicals released across special cell junctions known as synapses.

"Now we have found good evidence that the TGF-2 protein regulates the size of the packets released and thus the amount of neurotransmitter they contain," Prof McLennan said.

"This gives the protein a key role in allowing synaptic signalling to successfully occur."

Prof McLennan said previous studies looking at TGF-2 showed it relieved symptoms of early-stage motor neurone disease in mice.

"Unfortunately, while it is harmless to mice, TGF-2 is ... known to be highly toxic when administered to humans. Now that we are aware of how TGF-2 works we will look for other ways to take advantage of this signalling system to pursue non-toxic therapies," he said.

"Any resulting therapy would not be a cure for motor neurone disease, but may be able to alleviate symptoms during the early stages of the devastating condition."

The study was published in the United States journal Proceedings of the National Academy of Sciences.

- NZPA